FGF21 Induced by the ASK1-p38 Pathway Promotes Mechanical Cell Competition by Attracting Cells

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House mouse Mus musculus dispersal in East Eurasia inferred from 98 newly determined complete mitochondrial genome sequences

The Eurasian house mouse Mus musculus is useful for tracing prehistorical human movement related to the spread of farming. We determined whole mitochondrial DNA (mtDNA) sequences (ca. 16,000 bp) of 98 wild-derived individuals of two subspecies, M. m. musculus (MUS) and M. m. castaneus (CAS). We revealed directional dispersals reaching as far as the Japanese Archipelago from their homelands. Our phylogenetic analysis indicated that the eastward movement of MUS was characterised by five step-wise regional extension events: (1) broad spatial expansion into eastern Europe and the western part of western China, (2) dispersal to the eastern part of western China, (3) dispersal to northern China, (4) dispersal to the Korean Peninsula and (5) colonisation and expansion in the Japanese Archipelago. These events were estimated to have occurred during the last 2000–18,000 years. The dispersal of CAS was characterised by three events: initial divergences (ca. 7000–9000 years ago) of haplogroups in northernmost China and the eastern coast of India, followed by two population expansion events that likely originated from the Yangtze River basin to broad areas of South and Southeast Asia, including Sri Lanka, Bangladesh and Indonesia (ca. 4000–6000 years ago) and to Yunnan, southern China and the Japanese Archipelago (ca. 2000–3500). This study provides a solid framework for the spatiotemporal movement of the human-associated organisms in Holocene Eastern Eurasia using whole mtDNA sequences, reliable evolutionary rates and accurate branching patterns. The information obtained here contributes to the analysis of a variety of animals and plants associated with prehistoric human migration.Subject terms: Evolution, Genetic variation     

Physical Mapping of Rice Chromosomes 4 and 7 Using YAC Clones

Physical maps of rice chromosomes 4 and 7 were constructed bylanding yeast artificial chromosomes (YACs) along our high-densitymolecular linkage map. Using 114 DNA markers, 258 individualYACs were located on chromosome 4. Sixty-two out of 258 YACscarried two or more DNA marker positions and formed 16 contigswhich covered a total length of 17.1 cM. The other YACs werearranged to 23 positions. On chromosome 7, 203 individual YACswere landed on 109 DNA markers. Sixty-four out of 203 YACs formed15 contigs which covered a total length of 21.8 cM and 139 YACswere localized to 26 positions. Chromosomes 4 and 7 were coveredwith minimum tiling paths of 45 and 48 YACs, respectively. Takingthe average size of YAC insert DNA to be 350 kb and the entiregenome size to be 430 Mb, about 16–18 Mb of each chromosomeor an estimated 50% of their total lengths have been coveredwith YACs. Physical maps of these 2 chromosomes should be ofgreat help in identifying useful trait genes and unravelinggenetic and biological characteristics in rice.     

Ectomycorrhizal morphotypes of naturally grownAbies firma seedlings

Ectomycorrhizas of naturally grown Momi fir (Abies firma) seedlings were characterized based on morphological features of fungal partners. A total of 128 seedlings were collected over three years (1995–1997) from a 10×30 m plot where occurrences of ectomycorrhizal fungal fruitbodies were monitored for the same period. Thirty-seven morphologically distinct ectomycorrhizal types were distinguished based mainly on the color of ectomycorrhizas and the characteristics of fungal mantles. Type 37 was thought to beCenococcum geophilum because of the jet-black mycorrhizas and the characteristic structure of mantle surfaces. For half of the classified morphotypes, fungal partners were inferred to be the generaLactarius, Russula, andTuber, and unidentified Basidiomycetes, based on earlier references.